Safety device for internal combustion engines



P 1933. M. s. PARKHILL 1,925,846 SAFETY DEVICE FOR INTERNAL COMBUSTIQNENGINES Filed Jan. 9, 1930 INVEN TOR. Meat; ew pmdrh a m.

HIS A TTORNEY.

Patented Sept. 5, 1933 SAFETY DEVICE FOR INTERNAL COM BUSTION ENGINES vi Mortimer s. Parkhill, Corning, N. to Ingersoll-Rand Company,

Y., assignor Jersey City,

N. J., a corp-oration of New Jersey Application January 9, 1930. SerialNo. 419,705

1 Claim.

This invention relates to internal combustion engines, but moreparticularly to a safety device for engines of this type in which thefuel charge is electrically ignited.

One object of the invention is to prevent the operation of the engine atexcessive speeds.

Other objects will be in part obvious and in part pointed outhereinafter.

In the accompanying drawing illustrating one form of the invention andin which similar reference characters refer to similar parts,

Figure l is a side elevation of an internal combustion engine and itsignition system having the invention applied thereto,

Figure 2 is a transverse view taken through Figure 1 on the line 2-2looking in the direction indicated by the arrows, and

Figures 3 and a are sectional elevations taken through Figure 2 on thelines 3--3 and 4l look- 7 ing in the directions indicated by the arrows.

Referring more particularly to the drawing, A designates an internalcombustion engine which may be suitably supported by a base B as mayalso be an electrical current generating device,

such as a magneto C.

The magneto C may be actuated in any suitable and convenient manner, asfor instance, by a shaft D which is shown extending longitudinally O ofthe engine A and which may be operatively connected to the crank shaft(not shown) of the engine for imparting. rotary movement to the shaft D.The magneto C is shown supporting a distributor E from which lead cablesF to spark plugs G in the head H of the engine A.

. In accordance with the present invention means are provided forbringing the engine to a standstill whenever its speed exceeds thatwhich it may be considered desirable to maintain. To this end the engineis provided with a safety device designated generally by J and whichdevice is adapted to be associated with the shaft D in such a mannerthat it will be responsive to any acceleration of the shaft D above whatmay be determined as its normal speed.

The safety device comprises a contact K which is suitably secured to thebase B of the engine and is connected to the ground terminal L of themagento C by means of a cable 0. The contact K may be suitably insulatedfrom the base B by means of an insulator P which is arranged in a hole Qin the base B and through which hole the contact K extends.

Preferably the contact K is disposed closely adjacent the shaft D onwhich is arranged a bearing designated generally by R and comprising apair of plates S and T. The plate S is provided with a hub U whichencircles the shaft D and serves as an abutment for the plate T. Onlythe plate S is directly connected to the shaft D as by means of a key V,and the plate T is secured to the plate S by means of bolts W upon whichare disposed spacers in the form of sleeves X to prevent distortion ofthe outer extremities of the plates when the bolts W are threadedtightly into position.

Arranged on diametrically opposite sides of the plates S and T andmounted pivotally on two of the bolts W are a pair of centrifugalweights Y which are provided at one end with suitable apertures Z toreceive the spacers X.

The weights Y have lateral arms I) located-" adjacent the end of theweights wherein the apertures Z are formed. In each, arm b is disposed apin 0 to engage slots d in a circular plate e arranged rotatably uponthe hub Uof the plate S and between the weights Y.

Secured to one side of the plate 2 is a pin j which serves as an anchorfor one end of a spring 9 adapted to resist the centrifugal movement ofthe weights Y. The opposite end of 3 the spring 9 is seated against aspring seat which extends into a groove 7 in the plate e and wherein thespring 9 is also arranged.

The spring seat h has an integral threaded stem which extends through anarcuate slot o in the plate T, and on the stem is is threadeda nut 10whereby the spring seat It may be clamped fixedly to the plate T. Theslot 0 may be of suitable extent so that by shifting the spring seat hfrom one position to another along the}? length of the slot the tensionof the spring 1" may be varied to resist the outward movement of theweights Y.

Arranged between the contact K and the shaft D is a lever q having abore 1' near one end thereof to receive a pivot pin 8 which also extendsthrough lugs t on the base B. The aperture r is located near thelowermost end of the lever q, and at the opposite end of the lever is aweight u which normally tends to hold the lever q in an unbalancedposition.

The lever q carries an integral stop 11 which is adapted to engage ashoulder 11) on the base B when the lever q is held free from thecontact K. The stop 0 and the weight it of the lever lie in differentlongitudinal planes so that when the lever is in the raised positionillustrated in Figure 2, said lever will incline in the direction of theshaft D.

The following is a brief description of the operation of the invention:During the time the engine A is operating at normal speeds the pressureof the spring 9 will maintain the weights Y in substantially theretracted position illustrated in Figure 2. If, during the course of itsoperation the speed of the engine should exceed that which. itisrdesired to maintain, the free ends of the weights Y will moveoutwardly in the direction of the lever q. g

When the engine, and therefore also the shaft D, attains that speedwhiclr may be considered excessive, the weights Y will moveoutwardlyuntil they strike the weighted portion u of the lever q. Inthis way thelever q will be tilted about the pivot s and the weightedportion u will cause the lever q to drop on the contact This will havethe etfectot grounding the mag.-

engaging the plate to actuate the plate relatively to the bearing, andsprings within the plate and acting against the plate and the bearing.to resist the centrifugal movement of the weights.

- MORTIMER S. PARKI-IILL.

neto C so that the fuel charges in the cylinders 7

